Electronic cards are subject to interconnection standards or specifications that define, in three dimensions, the size of the cards and the slots into which these cards are inserted. These size constraints prevent production of elongate thermal slots that are thicker, or multiple, which would optimize heat exchange between the card and the frame.
Various elements can be used to cool an electronic card and its components by heat conduction. For example, it is possible to attach a heat sink to all or part of the electronic card, so as to remove the heat produced by the card to the outside such as the frame in which the electronic card may be fitted.
An electronic card generally has spots having a higher temperature than the rest of the card. These hot spots generally correspond to the locations of certain components, for example processors. To improve the removal of heat from these hot spots, it is possible to use heat pipes. The latter are long cylinders, often made of a metal (for example of copper or aluminum), that contain a fluid such as water. This water is in equilibrium between its gaseous phase and its liquid phase in the absence of any other gas. In the portion of the heat pipe near the component to be cooled, the water is heated and vaporizes, thereby storing energy from the heat emitted by this component. This gas then ascends the heat pipe and arrives near a cooling system where it is cooled until it condenses to become a liquid once more, releasing energy to the ambient air in the form of heat.
French patent application number FR 2 925 254 provides a cooling device, for an electronic card, using heat pipes. This device removes the heat produced by electronic components on the card and transfers this heat to points of contact between the card and the slot of the frame into which the card is inserted.
However, this device has a number of drawbacks. Firstly, the heat exchange area available between the card and the frame is limited by the standardized size of the slot. Also, it is not meant for optional installation. In other words, it cannot be installed on a card equipped with a standard heat sink, and once the device is installed on a card it is not possible to remove it without having to once more modify the heat sink associated with the card or the frame into which the card is inserted. Additionally, this device does not guarantee independent pathways of heat removal to the cold spot.